British Land’s West One retrofit: design and tunnelling constraints for engineers
Reviewed by Tom Sullivan
First reported on The Construction Index
30 Second Briefing
British Land has awarded McLaren a £99m design-and-build contract to retrofit and expand the late-1970s West One building above Bond Street Underground Station into 93,517 sq ft of premium offices over seven storeys. The scheme retains around 60% of the existing concrete frame, adds three extra office floors using a lightweight steel structure from second floor upwards, and reconfigures the block to two retail levels (basement and ground) with offices from first to seventh floors. Targeting NABERS 5*, BREEAM Excellent, EPC A and WELL Enabled, the project is constrained by a dense tunnel network, limiting new foundations to a single concrete core.
Technical Brief
- Design-and-build contract with McLaren is valued at £99m, combining retrofit and new-build elements.
- Allford Hall Monaghan Morris reconfigures internal layout, including enlarged office reception and revised retail–office split.
- Three extra office floors are stacked above the existing structure, with plant rooms concentrated at level eight.
- Lightweight steel frame from second floor upwards is used to increase storeys without breaching weight limits.
- Amenities upgrade includes new cycle storage, showers, and multiple external terraces plus second–third floor courtyard spaces.
- Construction must be sequenced around live commercial tenants and continuous operation of Bond Street Underground Station.
Our Take
British Land’s West One scheme in the United Kingdom sits alongside its One Appold Street refurbishment with Skanska in our database, signalling a deliberate portfolio push towards deep retrofits of existing concrete and steel frames rather than full demolitions in central London.
Retaining 60% of the existing concrete structure while targeting a NABERS 5‑star rating puts West One at the sharper end of London office refurbishments, where many schemes in our Infrastructure coverage still struggle to combine high retention ratios with top‑tier operational energy performance.
McLaren Construction’s appointment here follows its recent wins on Sizewell C support facilities and a 70MW Docklands data centre, suggesting the contractor is leveraging its growing £1bn‑plus turnover position to secure technically demanding, sustainability‑branded projects across both commercial and infrastructure sectors.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
Related Articles
Related Industries & Products
Construction
Quality control software for construction companies with material testing, batch tracking, and compliance management.
Tunnelling
Specialised solutions for tunnelling projects including grout mix design, hydrogeological analysis, and quality control.
QCDB-io
Comprehensive quality control database for manufacturing, tunnelling, and civil construction with UCS testing, PSD analysis, and grout mix design management.